The present invention is concerned with canisters of the type conventionally used for the storage and preservation of foodstuffs, for example, sugar, flour, rice, biscuits, snack foods, and the like. Such canisters are frequently provided in sets, and while normally used in the home, can also be used to contain foodstuffs for purchase in stores.
The principal problem with known canisters is the difficulty in obtaining an effective sealing or closing of the canister to provide a liquid tight and airtight container, while at the same time providing a lid or closure which effectively resists internal pressure build-up and is easily secured to and released from the canister body.
With regard to the problem of pressure build-up, both as the cover is mounted and due to any food-generated gases, it has in the past been known to provide vents. However, such vents will frequently affect the integrity of the seal, and the actual formation of the vents requires precision manufacturing techniques within rather confining parameters.